This invention relates to a technique for allowing a wide band and a high transfer rate to be used in a signal transmission apparatus and a signal reproduction apparatus in which a rotary transformer is used.
An apparatus is known which uses a rotary transformer as signal transmission means for transmitting a signal from a rotary system. For example, in a magnetic recording and/or reproduction apparatus in which a rotary head is used or a like apparatus, a rotary transformer is used in a circuit which transfers a reproduction signal from the rotor side to the stator side. In the circuit of the type described, the band is limited by the inductance of the magnetic head and the rotary transformer. In this regard, a reproduction amplifier is disposed on the stator side to improve the band characteristic.
The conventional circuit, however, has the following problem where it is tried to increase the bandwidth and the transfer rate.
In particular, the conventional circuit is disadvantageous in that, for example, where a magnetic resistive (MR) element is used as a head or in a like case, the bandwidth in reproduction is limited principally by the rotary transformer, more particularly by the inductance, coupling coefficient, floating capacitance and so forth of the rotary transformer.
In order to improve the rotary transformer, a method of raising the coupling coefficient of it, another method of decreasing the inductance of it and so forth can be used. However, for example, if it is tried to raise the coupling coefficient, then this has a bad influence in that the cost upon mass production rises. Therefore, the methods mentioned are restricted in improvement of the rotary transformer.